1. Field of the Invention
The present invention relates to a lift device and, more particularly, to an internally pulling type lift device for a chair armrest.
2. Description of the Related Art
A conventional externally pulling type lift device 1 for a chair armrest in accordance with the prior art shown in FIG. 5 comprises a support post 10, an adjusting pipe 11 movably mounted on the support post 10 and detachably locked on the support post 10 by a locking member 13, and an armrest support 12 mounted on the upper end of the support post 10. Thus, when the adjusting pipe 11 is unlocked from the locking member 13, the adjusting pipe 11 is movable relative to the support post 10 to adjust the height of the armrest support 12 relative to the support post 10 so as to adjust the height of the chair armrest.
However, the adjusting pipe 11 is movable on the support post 10 frequently, so that the adjusting pipe 11 easily rubs and wear the outer surface of the support post 10, thereby decreasing the aesthetic quality of the support post 10. In addition, the manufacturer needs to spray paint on the adjusting pipe 11 and the support post 10, thereby increasing the working time and increasing the costs of fabrication.